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Phase 1 Assessment of the Safety and Immunogenicity of an mRNA-
Lipid Nanoparticle
Vaccine Candidate Against SARS-CoV-2 in Human Volunteers
Peter Kremsner1,10,11, Philipp Mann6, Jacobus Bosch5, Rolf
Fendel1, Julian J. Gabor1, Andrea
Kreidenweiss1, Arne Kroidl3,4, Isabel Leroux-Roels2, Geert
Leroux-Roels2, Christoph
Schindler5, Mirjam Schunk3,4, Thirumalaisamy P. Velavan1,
Mariola Fotin-Mleczek9, Stefan
Müller6, Gianluca Quintini8, Oliver Schönborn-Kellenberger8,
Dominik Vahrenhorst9,
Thomas Verstraeten7, Lisa Walz6, Olaf-Oliver Wolz9, Lidia
Oostvogels6
1. Institute of Tropical Medicine, University Hospital Tübingen,
Tübingen, Germany
2. Ghent University Hospital, Ghent, Belgium
3. Division of Infectious Diseases and Tropical Medicine,
University Hospital, LMU
Munich, Germany
4. German Center for Infection Research (DZIF), partner site
Munich, Germany
5. Hannover Medical School (MHH), Hannover, Germany
6. Curevac AG, Frankfurt, Germany
7. P95 Epidemiology and Pharmacovigilance, Leuven, Belgium
8. Cogitars, Heidelberg, Germany
9. Curevac AG, Tübingen, Germany
10. German Center for Infection Research (DZIF), partner site
Tübingen,
Tübingen, Germany
11. Centre de Recherches Médicales de Lambaréné, Lambaréné,
Gabon
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ABSTRACT
There is an urgent need for vaccines to counter the COVID-19
pandemic due to infections with
severe acute respiratory syndrome coronavirus (SARS-CoV-2).
Evidence from convalescent
sera and preclinical studies has identified the viral Spike (S)
protein as a key antigenic target
for protective immune responses. We have applied an mRNA-based
technology platform,
RNActive®, to develop CVnCoV which contains sequence optimized
mRNA coding for a
stabilized form of S protein encapsulated in lipid nanoparticles
(LNP). Following
demonstration of protective immune responses against SARS-CoV-2
in animal models we
performed a dose-escalation phase 1 study in healthy 18-60
year-old volunteers.
This interim analysis shows that two doses of CVnCoV ranging
from 2 μg to 12 μg per dose,
administered 28 days apart were safe. No vaccine-related serious
adverse events were reported.
There were dose-dependent increases in frequency and severity of
solicited systemic adverse
events, and to a lesser extent of local reactions, but the
majority were mild or moderate and
transient in duration. Immune responses when measured as IgG
antibodies against S protein or
its receptor-binding domain (RBD) by ELISA, and SARS-CoV-2-virus
neutralizing antibodies
measured by micro-neutralization, displayed dose-dependent
increases. Median titers
measured in these assays two weeks after the second 12 μg dose
were comparable to the median
titers observed in convalescent sera from COVID-19 patients.
Seroconversion (defined as a 4-
fold increase over baseline titer) of virus neutralizing
antibodies two weeks after the second
vaccination occurred in all participants who received 12 μg
doses.
Preliminary results in the subset of subjects who were enrolled
with known SARS-CoV-2
seropositivity at baseline show that CVnCoV is also safe and
well tolerated in this population,
and is able to boost the pre-existing immune response even at
low dose levels.
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Based on these results, the 12 μg dose is selected for further
clinical investigation, including a
phase 2b/3 study that will investigate the efficacy, safety, and
immunogenicity of the candidate
vaccine CVnCoV.
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INTRODUCTION
The global COVID-19 pandemic due to the severe acute respiratory
syndrome coronavirus 2
(SARS-CoV-2) is causing uncontrolled illness around the world
with almost 50 million cases
and over 1 million deaths [1]. Although many infections are
asymptomatic or mild, more severe
cases produce respiratory distress which requires mechanical
ventilation in intensive care and
can result in death [2]. Increasing SARS-CoV-2 infection rates
may overwhelm critical care
capacity, with a consequential increase in mortality rate,
highlighting the urgent need for an
effective prophylactic vaccine to protect the immunologically
naïve population. A major
research and development effort to produce effective SAR-CoV-2
vaccines has been launched
globally, with 47 candidates currently in clinical testing [3].
One new approach applied in some
of these programs, is the use of mRNA coding for the required
protein antigen to produce a
human SARS-CoV-2 vaccine [4].
CureVac has developed and established an mRNA-based technology,
RNActive®, for
accelerated development of human vaccines [5]. Proof-of-concept
was demonstrated in a first-
in-human phase 1 study using chemically unmodified mRNA coding
for rabies virus
glycoprotein (RABV-G) [6]. That study found low responses of
anti-RABV-G neutralizing
antibodies that were dependent upon the route and mode of
administration of the mRNA
injection. Preclinical studies demonstrated improvement of the
immune responses in animal
models by encapsulating the mRNA in lipid nanoparticles (LNP)
[7]. Another human phase 1
study was performed with RABV-G mRNA-LNP formulations which
found that two 1 or 2 μg
doses elicited immune responses comparable to a three-dose
regimen of a licensed rabies
vaccine, and with acceptable tolerability [8].
In response to the global COVID-19 pandemic, the RNActive®
technology platform has been
applied to CVnCoV, an mRNA-LNP vaccine aimed at preventing
SARS-CoV-2 infection [9].
The target antigen for many of the SARS-CoV-2 vaccines in
development is the glycosylated
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spike (S) protein on the viral surface. S proteins from MERS
[10] and SARS-CoV viruses [11]
are essential for viral binding and uptake into mammalian cells,
and this is now confirmed for
the SARS-CoV-2 S protein [12,13]. The trimeric S protein
interacts with human angiotensin-
converting enzyme 2 (ACE2) receptors to allow intracellular
entry of the virus following
proteolytic cleavage of the S protein into its S1 and S2 domains
leading to fusion with the cell
membrane and release into the cell cytoplasm for viral
replication [12–15]. Inhibition of S
protein cleavage into the S1 and S2 domains by protease
inhibitors [14], antibodies to the
receptor-binding domain (RBD) of the S protein [16], or
antibodies to S protein from
convalescent COVID-19 patients [13] have all been protective in
preclinical models,
highlighting this protein as the target for vaccine development.
CVnCoV consists of non-
chemically modified mRNA encoding full-length S protein,
encapsulated in LNP. The coded
S protein includes two proline mutations (S-2P) previously been
shown to stabilize the
conformation of the S proteins for MERS-CoV [9] and SARS-CoV
[11]. mRNA was optimized
to provide a high expression level of S protein and a moderate
activation of innate immunity.
In rodent models, CVnCoV induces neutralizing antibodies and T
cell responses. and provides
lung protection in a hamster SARS-CoV-2- challenge model
[9].
We report an interim analysis of the first data from an ongoing
first-in-human phase 1 CVnCoV
trial of a two-dose primary schedule to assess the safety,
reactogenicity, and immunogenic ity
in healthy adults in two age strata (18–40 years and 41–60
years). Both SARS-CoV-2 naïve
and previously infected participants are included in the trial
to ensure that pre-existing
immunity has no effect on the assessed parameters.
METHODS
The first-in-human, placebo-controlled, blinded phase 1 trial of
CVnCoV enrolled healthy
adults (18 to 60 years). This dose-finding trial is conducted in
Hannover, Munich and
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Tübingen, Germany, and Ghent, Belgium. The study protocol was
approved by the appropriate
Investigational Review Boards (IRB) and national regulatory
authority for each site, and was
registered with ClinicalTrials.gov (Identifier: NCT 04449276).
All study procedures were
performed according to International Council for Harmonization
of Technical Requirements
for Pharmaceuticals for Human Use and Good Clinical Practice
guidelines. All participants
provided written informed consent at enrollment. The study was
monitored for safety by an
internal Safety Review Committee (iSRC) and a Data Safety
Monitoring Board (DSMB)
composed of independent external vaccine experts.
The primary objective was the evaluation of safety and
reactogenicity of 1 or 2 doses of
different dosages of CVnCoV administered by intramuscular
injection 28 days apart. The main
secondary objectives were the evaluation of the humoral immune
response measured by SARS-
CoV-2- S protein-specific IgG and RBD IgG (ELISA) antibodies, as
well as SARS-CoV-2
virus neutralizing antibodies.
Since screening for SARS-CoV-2 serostatus at baseline in large
clinical studies would be
unpractical, a subset of SARS-CoV-2 seropositive participants
were also included in the study
to assess if the baseline serostatus impacts any of the
parameters assessed.
Participants
Eligible participants of either sex, in good health based on
medical history and examination at
screening, were enrolled in two equal age groups (18–40 and
41–60 years). Main inclusion
criteria were a body mass index (BMI) ≥18.0 and ≤ 30.0kg/m2 and
being available for the
duration of the study. Main exclusion criteria were a known
elevated risk of exposure to SARS-
CoV-2 infection (e.g. healthcare personnel or those directly
involved in patient care or long-
term care), or any history of COVID-19 infection or exposure to
a COVID-19 infected
individual with two weeks prior to the study. Each dose level
includes a subset of known
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SARS-CoV-2 seropositive participants for whom the earlier
mentioned exclusion criteria did
not apply. The following exclusion criteria were to be applied
to all subjects: any current or
previous history of immunosuppressive disorder or therapy, any
previous confirmed infection
with SARS or MERS, and any known allergy to a vaccine component.
Also excluded were
active smokers within the previous year, pregnant or
breastfeeding women, study sponsors,
and study staff employees or relatives. Women of child-bearing
potential were required to have
a negative pregnancy test within three days before receiving
their first vaccination, and to use
an approved highly effective form of contraception from one
month before the first vaccination
until 3 months after the last vaccination.
Study design
This was a dosage escalation study, starting with 2 μg CVnCoV
and progressively increased
in subsequent groups with dosages of 4, 6, 8, and 12 μg. Higher
dosages of 16 and 20 μg are
currently being administered. For each dosage group there was a
sentinel cohort of two
participants in each of the two age groups with no history of
COVID-19. Sentinels were
vaccinated (two vaccinees per age group, open label) and
monitored for 60 hours. The iSRC
and DSMB chair assessed the safety data from the first 24 hours
of these sentinels before
approving the vaccination of four additional participants in
each age group (open label, subjects
without a history of COVID-19). After assessing safety data for
60 hours, the iSRC and DSMB
approved the vaccination of the remaining participants of that
dosage group (including placebo
subjects and subjects known to be seropositive for SARS-CoV-2,
randomized and blinded) and
the sentinels of the next higher dosage group. This procedure
was then repeated until all groups
were vaccinated for dose levels up to 8 µg. The procedure was
the same for 12 µg dose, but all
subjects were open label, without placebo control.
Vaccine
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The study vaccine, CVnCoV, is an investigational LNP-formulated
RNActive® SARS-CoV-2
vaccine composed of the active pharmaceutical ingredient, an
mRNA that encodes a pre-fusion
conformation stabilized version of the full length spike (S)
protein of SARS-CoV-2 virus, and
four lipid components: cholesterol,
1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC),
PEG-ylated lipid and a cationic lipid. The placebo administered
in the control arms consists of
0.9% NaCl. Each 0.5 mL dose was administered by intramuscular
injection in the deltoid. All
administrations were performed by unblinded study staff who had
no role in data collection for
safety or immunogenicity assessments.
Safety assessments
All participants remained under direct supervision of site
personnel for 4 hours following
administration of their assigned injection. Participants then
recorded in diary cards solicited
local (injection-site pain, redness, swelling, and itching) and
systemic (headache, fatigue,
chills, myalgia, arthralgia, nausea/vomiting, and diarrhea)
adverse events and daily temperature
using a supplied thermometer for 7 days after each vaccination,
and any unsolicited adverse
events until the next study visit 28 days after vaccination. All
solicited AEs were graded for
severity as Grade 1 (mild: easily tolerated, causing minimal
discomfort and not interfering with
everyday activities), Grade 2 (moderate: causes sufficient
discomfort to interfere with normal
everyday activities) and Grade 3 (severe: prevents normal
everyday activities) using the FDA
Grading Scale [17] (see Supplementary material). The
investigator reviewed the severity
gradings on the diary cards and used their clinical judgement to
assess causality as either related
(there is a reasonable causal relationship between the trial
vaccine and the AE) or unrelated
(there is no reasonable causal relationship between the trial
vaccine and the AE). Blood
samples were also drawn on Days 1, 2, 8, 30 and 36 to perform
laboratory safety assessments,
graded according to the FDA Grading Scale [17].
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Serious adverse events (SAE), defined as life-threatening
events, events resulting in death,
events requiring inpatient hospitalization or prolongation of
existing hospitalization, or events
resulting in persistent disability/incapacity, were to be
reported to the investigator immediately ,
who notified the sponsor. Investigators could also consider
additional medical events to be
SAEs. Monitored adverse events of special interest (AESI)
included potential immune
mediated diseases and COVID-19 disease. In the event of a
confirmed COVID-19 infection
the participant or treating health care provider were to
complete a specific diary card. Safety
will continue to be monitored for one year after the last
vaccination.
Immunogenicity assessments - IgG ELISA
Blood samples were drawn on Days 1 and 29, before each of the
two vaccinations, and on Days
8, 15, 36, 43 and 57 for immunogenicity assessments. Sera were
prepared and stored at -80°C
before shipping on dry-ice for measurement of the immune
responses in accordance with EMA
“Guideline on bioanalytical method validation” at Vismederi
S.r.l., Siena, Italy. Anti-SARS-
CoV-2-specific IgG levels were measured by ELISA. Briefly,
plates were coated with 1µg/ml
of SARS-CoV-2 Spike (Spike S1+S2 ECD-His Recombinant Protein,
Cat: 40589-V08B1; Sino
Biological, Chesterbrook, PA, USA) or Spike RBD (Spike RBD-His
Recombinant Protein,
Cat. 40592-V08H; Sino Biological) recombinant protein. Blocking
was performed in 5% milk.
Coated plates were incubated with heat-inactivated (56°C for 30
min) human serum in a 1:2-
fold serial dilution (starting at 1:100). Antigen-specific IgG
detection was performed with goat
anti-human IgG-HRP conjugate (Cat: A80-104P-93, Bethyl
Laboratories, Montgomery, Texas,
USA) and tetramethyl benzidine (TMB) substrate (Bethyl
Laboratories, Montgomery, Texas,
USA) at OD 450 nm. The titer was determined as the reciprocal of
the highest serum dilution
that is over the pre-determined cut-off OD value (limit of
detection plus matrix effect) and
reported as geometric mean titer (GMT) of duplicates. If no
antibody was detectable (all
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dilutions below cut-off OD), an arbitrary titer value of 50
(half of the limit of quantification)
was reported.
Immunogenicity assessments – Neutralizing activity
SARS-CoV-2 virus neutralization titers were determined by a
micro-neutralization assay with
Cytopathic Effect (CPE)-read out as described previously [17].
In brief, heat-inactivated (56°C
for 30 min) human serum was serially diluted 1:2 (starting at
1:10) and incubated with wild
type SARS-CoV-2 virus strain 2019-nCov/Italy-INMI1 at 37⁰C 5%
CO2 for 1 hour.
Afterwards, semi-confluent Vero E6 cells (ATCC, Cat.1586) were
incubated with the virus -
serum mixtures at 37°C 5% CO2 for 3 days. Cells were assessed
for virus-induced CPE by light
microscopy. The neutralization titer was determined as the
reciprocal of the highest serum
dilution that protected more than the 50% of cells from CPE and
reported as geometric mean
titer (GMT) of duplicates. If no neutralization was observed, an
arbitrary titer value of 5 (half
of limit of quantification) was reported.
Reference human convalescent sera
The pool of human COVID-19 convalescent sera consisted of 67
samples collected mainly
between 4 to 8 weeks after diagnostic confirmation of SARS-CoV-2
infection. Sera were either
purchased from MTG Group (Van Nuys, California, USA) under the
MTG Group PROTOCOL
NO: MTG-022, Ethic Approval Sterling Institutional Review Board
ID: 3764, or were donated
by the Universitätsklinikum, Tübingen. These samples included 16
sera from hospitalized
patients, the remaining 51 being from patients who were not
hospitalized but manifested with
clear COVID-19 illness with various symptoms.
Statistics
As this is an exploratory study results are presented
descriptively. The sample size was not
based on any hypothesis but was intended to allow estimation of
the probability that the true
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rate of adverse reactions for each dose lies in an acceptable
safety range. A minimum of 12
evaluable participants per dose and per age group was considered
adequate for this purpose ,
but in anticipation of drop-outs and with uncertainty about the
proportion which would
subsequently be found to have prior asymptomatic exposure to
SARS-CoV-2 a conservative
number of 48 per group (24 in each age group) was chosen. As
this is a dose-escalation study
not all safety and immunogenicity are yet available for the
later groups (higher doses) in this
interim analysis, and safety and immunogenicity data are not
presented according to age group
or retrospectively confirmed baseline serostatus for SARS-CoV-2.
Such analyses will be
performed and full details according to these factors will be
published when the full data set is
available.
Safety data was analyzed in the Safety Set composed of all those
who received one study
administration (vaccine or placebo) and for whom any
post-vaccination safety data was
available. Safety data is presented descriptively as numbers of
participants and percentages of
each group having a specific solicited AE, together with
severity. SAEs and AESIs are
described by case. The primary endpoints for the safety
objective were the frequencies of
SAEs, Grade 3 solicited AEs within 60 hours of vaccination,
frequencies and severity of
solicited AEs within 7 days of vaccination, and the occurrence,
intensities, and causality of
unsolicited AEs with 28 days of vaccination. In this interim
report of safety data we distinguis h
between dosage groups, but not between age groups.
Immunogenicity was analyzed in all subjects who received both
doses and who had no protocol
deviation. Secondary immunogenicity endpoints are the
proportions of participants
seroconverting for SARS-CoV-2 S protein or RBD IgG and
neutralizing antibodies, as
measured by ELISA and micro-neutralization assay, respectively.
Seroconversion is defined
as a four-fold increase in titer over baseline. Data are
presented as group median titers (with
2th and 75th percentiles) of the individual antibody GMTs.
Immunogenicity data are presented
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graphically for individuals who received both vaccinations and
per groups at time-points for
which data is available.
Data are presented separately for subjects known to be
SARS-CoV-2 seropositive at baseline ,
and who were enrolled in the 2 or 4 µg dose levels.
To analyze translation of binding into neutralizing antibodies,
for every subject and visit, the
ratios between VNT to ELISA RBD and ELISA Spike were generated
individually, and the
median drawn on those aggregations per dose and visit, and
compared to the results from the
sera conversion panel used.
RESULTS
Demographics
By the time of this interim analysis 248 adults were enrolled
and assigned to the different study
groups. Of these, 245 received their first vaccination or
placebo injection (Figure 1).
Compliance was good, with 231 (94%) receiving their second
administration. The mean age
overall was 38.6 years (± 12.9 S.D.) and there were 142 (57%)
men and 106 (43%) women,
the mean BMI was 23.8 kg/m2 (± 2.63 S.D.). The majority were
described as white (237 [96%])
and non-Hispanic or Latino (242 [98%]). These demographics were
consistent across the
vaccine and placebo groups (Table 1).
A total of 17 participants, 15 vaccinees and 2 placebo
recipients, did not receive the second
dose administration. Nine were unable to attend the visit, four
of them because of an unrelated
concurrent AE. Four vaccinees discontinued participation in the
study before Day 29. Four
vaccinees did not receive their second dose because of an AE
following the first dose
administration, three because Grade 3 AEs, and one because of a
potential allergic reaction.
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Demography of subjects known to be SARS-CoV-2 seropositive at
baseline is presented in
Table 7.
Safety
The primary objective to demonstrate the safety of CVnCoV was
shown with no vaccine-
related SAEs or AESIs reported. Three SAEs (Table 2) reported
were cases of a complicated
fracture of the humerus, abdominal pain, and monoplegia of the
right foot, none of which were
considered to be related to vaccination.
Overall, there was a dose-dependent increase in the incidence
and severity of local solicited
AEs, illustrated in Figure 2. The vast majority of these reports
were of Grade 1 and 2 injection
site pain (Table 3); cases of severe pain usually had onset
within 24 hours of vaccination,
decreased in severity and resolved within 48 hours. The
incidence of reactions was similar after
the second dose, but lower in severity.
Systemic reactogenicity in terms of frequency and severity
increased with dose level. All 12
μg dose participants reported at least one solicited systemic AE
(Figure 2). Systemic AEs
displayed similar overall rates after the first and second
vaccinations, but the severity of these
increased for the second dose in the groups receiving the 4 μg
to 12 μg dose. For example, one
of the 12 μg recipients had Grade 3 systemic AEs after the first
dose compared with 3 after the
second dose. Most Grade 3 systemic AEs had decreased in severity
or resolved within 24 hours,
all did so with 72 hours. The most frequent solicited systemic
AEs were mild or moderate
headache and fatigue, followed by myalgia and chills. Overall,
fever was observed less
frequently.
Unsolicited AEs were reported by the majority of participants in
all groups, about half of these
being considered to be related to the study procedures. Many of
the unsolicited AEs were the
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same type as solicited AEs such as headache or fatigue but
occurred outside of the 7-day
solicitation period.
Laboratory adverse events were rare, with no specific pattern
observed other than strictly
transient lymphopenia, observed the day after vaccination and
thought to represent lymphocyte
redistribution related to the mode of action (data not shown)
[19].
Subjects known to be SARS-CoV-2 seropositive at baseline overall
experienced less
reactogenicity after vaccination with either 2µg or 4µg of
CVnCoV (Tables 8 and 9).
Immunogenicity
Strong immune responses were observed in all vaccine groups as
illustrated in Figures 3, 4 and
5 using all three assays, including in subjects who were known
to be SARS-CoV-2 seropositive
at baseline. As no responses were observed in placebo
recipients, they are not included in the
following descriptions.
In subjects Figure 3 shows the immune response as ELISA IgG
antibodies against the S protein
with low but variable median titers in the baseline samples
(placebo group is not shown as
there were no changes in median values over the 50 day period
shown). At Day 29, four weeks
after the first dose, there were small dose-dependent increases
with seroconversion rates of 6–
28% across vaccine groups (Table 5). On Day 36, 7 days after the
second dose, there was a
more marked increase in all groups with 49–82% seroconverting.
This rate continued to
increase to 79–91% at Day 43 when median titers were 1712
(25th–75th percentile: 789–3132),
2205 (1493–3183), 2839 (1232–7002), 3287 (1470–5770), and 5463
(2675–7132), in 2, 4, 6,
8 and 12 μg groups, respectively. Samples in the 8 μg group from
Day 57, four weeks after the
second dose, show a small decline in IgG median titers to 1825
(879–2834), but overall these
persisted above baseline and the Day 29 (pre-second dose)
values. Notably, the value at Day
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43 in the 12 μg group was comparable to the median titer of 6381
(5400–12432) in the group
of 67 convalescent sera.
When IgG antibody titers against S protein RBD were assessed
(Figure 4), an evident response
in the 8 μg group data (only group with a full data set in this
interim analysis) was shown at
Day 29 after one dose. The marked increases in titers 7 days
(Day 36) after the second dose
were also observed when seroconversion rates were 17–66% (Table
5). There was a further
increase by Day 43 when the seroconversion rates were 83% and
91% in the 8 and 12 μg groups
with median titers of 1240 (349–2952) and 1007 (678–3141),
respectively, which were
comparable to the median of 1448 (726–5391) observed in
convalescent sera.
These observations of IgG antibody responses to S protein and
RBD translated into SARS-
CoV-2 viral neutralizing activity, as shown in Figure 5. This
response was less obviously dose-
dependent from the available samples, but across the groups
34–64% had seroconverted at Day
36 (7 days after the second dose) from baseline. This rate
continued to increase to Day 43 when
100% of the 12 μg group (n = 11) had seroconverted. The median
neutralizing titer in this group
(113 MNT50 [28.3–113]) on Day 43 was the same as that observed
in convalescent sera (113
MNT50 [56.6–453]). In contrast to S protein IgG levels, the 8 μg
group median neutralizing
titers at Day 43 (56.5 MNT50 [20.0–113]) were generally
maintained to Day 57 (56.6 MNT50
[24.8–125]).
Immunogenicity of CVnCoV in subjects known to be SARS-CoV-2
seropositive at baseline is
presented in Figure 6. After vaccination with either with 2µg or
4µg of CVnCoV, a rapid
increase in antibody titers is shown within one week post first
vaccination. This was observed
for both binding and neutralizing antibodies. The effect of a
second dose was less pronounced;
antibody titers remained stable at least up to day 57.
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The analysis of the ratio between binding and neutralizing
antibodies (VNT to ELISA RBD
and ELISA Spike) was performed for the the selected dose 12 mcg
and is presented in Table
6. At Day 43 in the study (i.e. after two doses of CVnCoV) the
corresponding median of these
ratios are comparable of those measured in the convalescent sera
(HCS = Human Convalescent
Sera) (VNT to ELISA Spike: 0.0218 12 mcg, 0.0213 HCS & VNT
to ELISA RBD: 0.0806
12 mcg, 0.0832 HCS).
DISCUSSION
In this ongoing phase 1 clinical trial, we are investigating
increasing dose levels, from 2 to 12
µg of the mRNA vaccine candidate CVnCoV in a two-dose schedule
in healthy adults from 18
to 60 years of age. We present here an interim report of data
obtained so far. We found that the
vaccine was safe and showed an acceptable reactogenicity profile
at all levels, including a
subset of subjects who were known to be SARS-CoV-2 seropositive
at baseline. Compliance
with the vaccination schedule was high, with only four subjects
not receiving the second dose
due to AEs. There were no vaccine-related SAEs and although the
incidence and severity of
solicited adverse reactions appears to increase at increasing
dose levels, reactogenicity was not
dose-limiting, and higher dose levels (16 μg and 20 μg) are
currently being investigated.
Observed local reactions were almost exclusively cases of
transient mild to moderate injection
site pain; of the 415 total administered doses of CVnCoV at any
dosage only three resulted in
transient severe local pain, all after the first dose (one each
in the 2, 4 and 8 µg groups). The
frequency and severity of solicited systemic AEs increased with
dosage level and were
generally more frequent and of higher intensity after the second
dose than the first, as has been
observed with other mRNA SARS-CoV-2 vaccine candidates [20–22].
These systemic AEs
mainly consisted of transient mild or moderate headache and
fatigue, and to a lesser extent
myalgia and chills. Overall, fever was observed less frequently.
Severe solicited AEs usually
decreased or disappeared rapidly, mostly within 24–48 hours of
onset. The reactogenicity
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profile, with limited presence of fever but symptoms like
fatigue, headache and chills, is
probably associated with the postulated mechanism of action and
induction of an innate
immune response mediated by interferon and other
immune-stimulatory cytokines.
Th1 cytokines are important for development of T cell responses,
CD4 T cell help is required
for good induction of memory B cells. Moreover, such a T-helper
cell type 1 (Th1) biased
immune response is desirable for the development of a SARS-CoV-2
prophylactic vaccine,
due to the hypothetical concern for immune-mediated disease
enhancement observed in
preclinical studies for other coronaviruses. IFN type 1
signaling has been also described in
COVID patients as a critical pathway to control disease
[23,24].
All investigated dosages elicited an immune response against
SARS-CoV-2. In this interim
report, induction of an adaptive humoral immune response was
demonstrated by the increase
in neutralizing antibodies, with 56–77% of participants
achieving VNT seroconversion two
weeks after two doses of 2–8 μg, and 100% seroconverting two
weeks after two 12 μg doses.
This neutralizing activity was associated with marked S
protein-specific and RBD-specific IgG
antibody responses. S protein IgG and VNT responses were
detectable after the first
vaccination, but all markedly increased within 7 days of the
second vaccination indicating
efficient priming by the first dose. In the 8 μg group the
immune response persisted up to at
least Day 57, the last time-point with data currently
available.
Since an imbalance between binding versus neutralizing
antibodies could hypothetically lead
to immune-mediated disease enhancement, we investigated the
ratio neutralizing/binding
antibodies both for the S Spike protein as for RBD in the study
participants. We calculated
such ratios on an individual basis for vaccinated study
participants as well as for convalescent
patients (Table 6). We observed that the ratio post vaccination
is very similar as the ratio
measured in sera from convalescent patients after natural
infection. This observation is also
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in line with the mechanism of action of CVnCoV which mimics
natural immune response to
RNA viruses.
Data in SARS-CoV-2 seropositive subjects show CVnCoV is well
tolerated, supporting
further use of the candidate vaccine in future clinical
development and a broader population
without the need for previous testing for serostatus and
excluding seropositive subjects.
Furthermore, the data show that good memory responses are
induced by the natural
infection, since even in subjects with low antibody titers at
baseline, low doses of CVnCoV
(either 2µg or 4µg ) were able to expand antibody titers by more
than a factor 10 within one
week after the first vaccination. This supports the role of
memory cells to provide a long term
protection to SARS-CoV-2.
Our recently shared preclinical data in a hamster model showed
good priming followed
vaccination with low dose of CVnCoV or single vaccination and
rapid boosting of neutralizing
antibodies followed virus challenge. This was comparable to the
groups vaccinated with two
doses of vaccine [9]. The available preclinical and clinical
data are indicative of a functional
immune response mimicking the natural responses to infection,
including a potent induction of
memory. More analyses on T- and B-cell memory responses are
currently ongoing in this
clinical study, as well as in preclinical studies with CVnCoV
and will further inform the unique
mechanism of action of this mRNA vaccine candidate.
The study is ongoing with additional testing of higher doses (16
μg and 20 μg) to investigate
the boundaries of the safety window and completion of the
assessments of the present groups,
with follow up foreseen until at least 1-year post vaccination.
Based on the need to adequately
balance an acceptable reactogenicity profile with a strong
immune response in the range of
convalescent sera (including 100% seroconversion for VNT), the
12 μg dosage has been
selected for further investigation in phase 2 and 3 studies,
most notably in a phase 2b/3 study
to assess efficacy and safety in 36,500 participants that will
begin in the coming weeks.
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DECLARATION OF COMPETING INTEREST
MFM, PM, SM, LO, GQ, DV, LW, and OOW were employed by the study
sponsor at the time
of the study, OSK and TV are paid consultants for the study
sponsor, other authors have no
conflicts to declare.
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REFERENCES
1. Johns Hopkins University of Medicine, Coronavirus Resource
Center (November 3,
2020) https://coronavirus.jhu.edu/map.html.
2. Tan E, Song J, Deane AM, Plummer MP. Global impact of
COVID-19 infection
requiring admission to the intensive care unit: a systematic
review and meta-analysis.
Chest. 2020 Oct 15:S0012-3692(20)34906-0. doi:
10.1016/j.chest.2020.10.014.
3. WHO. DRAFT landscape of COVID-19 candidate vaccines–3
November 2020.
https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-
vaccines (accessed Nov 3, 2020).
4. Jackson NAC, Kester KE, Casimiro D, Gurunathan S, DeRosa F.
The promise of mRNA
vaccines: a biotech and industrial perspective. NPJ Vaccines.
2020;5: 11.
5. Rauch S, Lutz J, Kowalczyk A, Schlake T, Heidenreich R.
RNActive® technology:
generation and testing of stable and immunogenic mRNA vaccines.
Methods Mol Biol
2017; 1499:89–107.
6. Alberer M, Gnad-Vogt U, Hong HS, Mehr KT, Backert L, Finak G,
et al. Safety and
immunogenicity of a mRNA rabies vaccine in healthy adults: an
open-label, non-
randomised, prospective, first-in-human phase 1 clinical trial.
Lancet 2017; 390:1511–
20.
7. Lutz J, Lazzaro S, Habbeddine M, Schmidt KE, Baumhof P, Mui
BL, et al. Unmodified
mRNA in LNPs constitutes a competitive technology for
prophylactic vaccines. NPJ
Vaccines. 2017; 2:29.
8. Aldrich C, Leroux-Roles I, Huang KB, et al. First
proof-of-concept of a low-dose
unmodified mRNA-based rabies vaccine formulated with lipid
nanoparticles in human
volunteers: a phase 1 trial. Vaccine 2020: submitted for
publication.
9. Rauch S, Roth N, Schwendt K, et al. mRNA based SARS-CoV-2
vaccine candidate
CVnCoV induces high levels of virus neutralizing antibodies and
mediates protection in
rodents. Preprint at:
https://www.biorxiv.org/content/10.1101/2020.10.23.351775v1
(2020).
10. Letko M, Marzi A, Munster V. Functional assessment of cell
entry and receptor usage
for SARS-CoV-2 and other lineage B betacoronaviruses. Nat
Microbiol 2020;5: 562–9.
. CC-BY-ND 4.0 International licenseIt is made available under a
perpetuity.
is the author/funder, who has granted medRxiv a license to
display the preprint in(which was not certified by peer
review)preprint The copyright holder for thisthis version posted
November 9, 2020. ; https://doi.org/10.1101/2020.11.09.20228551doi:
medRxiv preprint
https://doi.org/10.1101/2020.11.09.20228551http://creativecommons.org/licenses/by-nd/4.0/
-
21
11. Pallesen J, Wang N, Corbett KS, et al. Immunogenicity and
structures of a rationally
designed prefusion MERS-CoV spike antigen. Proc Natl Acad Sci U
S A
2017;114:E7348-57.
12. Kirchdoerfer RN, Wang N, Pallesen J, et al. Stabilized
coronavirus spikes are resistant to
conformational changes induced by receptor recognition or
proteolysis. Sci Rep
2018;8:15701.
13. Huang Y, Yang C, Xu X-f, Xu W, Liu S-w. Structural and
functional properties of
SARS-CoV-2 spike protein: potential antivirus drug development
for COVID-19. Acta
Pharmacologica Sinica 2020;41:1141–9.
14. Hoffmann M, Kleine-Webber H, Schroeder S, et al. SARS-CoV-2
cell entry depends on
ACE2 and TMPRSS2 and is blocked by a clinically proven protease
inhibitor. Cell
2020:181:271–80.
15. Shang J, Wan Y, Luo C, et al. Cell entry mechanisms of
SARS-CoV-2. PNAS
2020;117:11727–34.
16. Yang J, Wang W, Chen Z, et al. A vaccine targeting the RBD
of the S protein of SARS-
CoV-2 induces protective immunity. Nature 2020; 586:572–7.
17. US Department of Health and Human Services. Food and Drug
Administration (FDA).
Guidance for Industry. Toxicity Grading Scale for Healthy Adult
and Adolescent
Volunteers Enrolled in Preventive Vaccine Clinical Trials. 2007.
Available from:
https://www.fda.gov/downloads/BiologicsBloodVaccines/GuidanceComplianceRegulato
ryInformation/Guidances/Vaccines/ucm091977.pdf. Accessed
November 8, March 2020.
18. Manenti A, Maggetti M, Elisa Casa E, et al. Evaluation of
SARS-CoV-2 neutralizing
antibodies using a CPE-based colorimetric live virus
micro-neutralization assay in
human serum samples. J Med Virol 2020; 92:2096–104.
19. Kamphuis E, Junt T, Waibler Z, Forster R, Kalinke U. Type I
interferons directly
regulate lymphocyte recirculation and cause transient blood
lymphopenia. Blood
2006;108:3253–61.
20. Jackson LA, Anderson EJ, Rouphael NG, et al. An mRNA vaccine
against SARS-CoV-2
— preliminary report. N Engl J Med 2020: Published on-line July
14, 2020. doi:
10.1056/NEJMoa2022483.
. CC-BY-ND 4.0 International licenseIt is made available under a
perpetuity.
is the author/funder, who has granted medRxiv a license to
display the preprint in(which was not certified by peer
review)preprint The copyright holder for thisthis version posted
November 9, 2020. ; https://doi.org/10.1101/2020.11.09.20228551doi:
medRxiv preprint
https://doi.org/10.1101/2020.11.09.20228551http://creativecommons.org/licenses/by-nd/4.0/
-
22
21. Anderson van J, Rouphael NG, Widge AT, et al. Safety and
immunogenicity of SARS-
CoV-2 mRNA-1273 vaccine in older adults. N Engl J Med 2020:
Published on-line
September 29, 2020. doi: 10.1056/NEJMoa2028436
22. Walsh EE, Frenck R, Falsey AR, et al. RNA-based COVID-19
vaccine BNT162b2
selected for a pivotal efficacy study. Preprint at :
https://www.medrxiv.org/content/10.1101/2020.08.17.20176651v2.full.pdf
23. Hadjadj J, Yatim N, BarnabeiL, et al. Impaired type
interferon activity and exacerbated
inflammatory responses in severe Covid-19 patients. Science
2020; 369:718–724.
24. Bastard P, Rosen LB, Zhang Q, et al. Autoantibodies against
type I IFNs in patients with
life-threatening COVID-19. Science 2020; 370:eabd4585. doi:
10.1126/science.abd4585.
. CC-BY-ND 4.0 International licenseIt is made available under a
perpetuity.
is the author/funder, who has granted medRxiv a license to
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Tables and Figures pertaining to subjects not known to be
seropositive at baseline (Table 1 to 5 and Figures 1 to 5)
Table 1. Demographics of the enrolled study population included
in this interim analysis by group
Group 1 2 3 4 5 6
2 μg 4 μg 6 μg 8 μg 12 μg Placebo
N= 47 48 48 45 28 32
Age (years)
Mean 38.2 39.1 38.6 38.2 37.4 40.1
SD 12.5 13.2 12.7 13.1 13.5 13.5
range (18–60) (19–59) (20–59) (20–59) (19–59) (19–60)
Male n (%)
27 (57) 25 (52) 31 (65) 27 (60) 17 (61) 15 (47)
Female 20 (43) 23 (48) 17 (35) 18 (40) 11 (39) 17 (53)
BMI
(kg/m2)
Mean 23.6 24.2 24.3 23.6 23.6 23.1
SD (2.54) (2.77) (2.67) (2.65) (2.56) (2.48)
Race n (%)
Asian 0 0 2 (4) 2 (4) 0 1 (3)
Brazilian 1 (2) 0 0 0 0 0
Black 1 (2) 0 0 0 0 0
White 43 (91) 48 (100) 44 (92) 43 (96) 28 (100) 31 (97)
Other or unknown 1 (2) 0 2 (4) 0 0 0
Ethnicity n (%)
Hispanic or Latino 3 (6) 0 2 (4) 0 0 0
Not Hispanic or Latino
44 (94) 48 (100) 46 (96) 45 (100) 27 (96) 32 (100)
Other or unknown 0 0 0 0 1 (4) 0
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Table 2. Unsolicited AEs, SAEs and AESIs after vaccination
Severity 2 μg 4 μg 6 μg 8 μg 12 μg Placebo
N = 47 48 48 45 28 32
After first dose
Unsolicited Any 25 (54.3) 32 (66.7) 35 (72.9) 30 (66.7) 21
(75.0) 18 (56.3)
Related 8 (17.4) 19 (39.6) 18 (37.5) 19 (42.2) 12 (42.9) 5
(15.6)
SAEs Any 0 0 1 (2.1) 0 1 (3.6) 1 (3.1)
Related 0 0 0 0 0 0
AESI Any 0 0 0 0 0 0
AEs leading to discontinuation or withdrawal
Any 1 (2.1) 1 (2.1) 1 (2.1) 0 1 (3.6) 1 (3.1)
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Table 3. Solicited local AEs with severity after one dose
Severity 2 μg 4 μg 6 μg 8 μg 12 μg Placebo
N = 46 48 48 45 28 32
After first dose
Pain
Any 32 (69.6) 42 (87.5) 38 (79.2) 40 (88.9) 26 (92.9) 4
(12.5)
Mild 30 (65.2) 38 (79.2) 32 (66.7) 26 (57.8) 17(60.7) 4
(12.5)
Moderate 2 (4.3) 3 (6.3) 5 (10.4) 11 (24.4) 9 (32.1) 0
Severe 0 1 (2.1) 1 (2.1) 1 (2.2) 0 0
Redness Any 0 0 0 0 0 0
Swelling
Any 0 4 (8.3) 1 (2.1) 0 1 (3.6) 0
Mild 0 4 (8.3) 1 (2.1) 0 1 (3.6) 0
Moderate 0 0 0 0 0 0
Severe 0 0 0 0 0 0
Itching
Any 0 1 (2.1) 5 (10.4) 3 (6.7) 2 (7.1) 1 (3.1)
Mild 0 1 (2.1) 5 (10.4) 3 (6.7) 2 (7.1) 1 (3.1)
Moderate 0 0 0 0 0 0
Severe 0 0 0 0 0 0
After second dose
N= 44 44 45 41 26 30
Pain
Any 24 (54.5) 34 (77.3) 30 (66.7) 34 (82.9) 22 (84.6) 1
(3.3)
Mild 24 (54.5) 32(72.7) 25(55.5) 29 (70.7) 17 (65.4) 1 (3.3)
Moderate 0 2 (4.5) 5(11.1) 5 (12.2) 5 (19.2) 0
Severe 0 0 0 0 0 0
Redness Any 0 0 0 0 0 0
Swelling
Any 0 1 (2.3) 0 0 0 0
Mild 0 1 (2.3) 0 0 0 0
Moderate 0 0 0 0 0 0
Severe 0 0 0 0 0 0
Itching
Any 0 1 (2.3) 2 (4.4) 1 (4.9) 1 (3.8) 0
Mild 0 1 (2.3) 2 (4.4) (4.9) 1 (3.8) 0
Moderate 0 0 0 0 0 0
Severe 0 0 0 0 0 0
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Table 4a. Solicited systemic AEs with severity within 7 days
after the first dose
Severity 2 μg 4 μg 6 μg 8 μg 12 μg Placebo
N = 46 48 48 45 28 32
Fever
Any 3 (6.5) 10 (20.8) 16 (33.3) 19 (42.2) 16 (57.1) 0
Mild 2 (4.3) 6 (12.5) 11 (22.9) 11 (24.4) 6 (21.4) 0
Moderate 1 (2.2) 2 (4.2) 4 (8.3) 4 (8.9) 6 (21.4) 0
Severe 0 2 (4.2) 1 (2.1) 4 (8.9) 4 (14,.3) 0
Headache
Any 22 (47.8) 36 (75.0) 34 (70.8) 38 (84.4) 25 (89.3) 10
(31.3)
Mild 16 (34.8) 22 (45.8) 15 (31.3) 13 (28.9) 2 (7.1) 8
(25.0)
Moderate 4 (8.7) 12 (25.0) 14 (29.2) 19 (42.2) 20 (71.4) 2
(6.3)
Severe 2 (4.3) 2 (4.2) 5 (10.4) 6 (13.3) 3 (10.7) 0
Fatigue
Any 22 (47.8) 35 (72.9) 39 (81.3) 39 (86.7) 27 (96.4) 15
(46.9)
Mild 16 (34.8) 20 (41.7) 20 (41.7) 19 (42.2) 7 (25.0) 13
(40.6)
Moderate 4 (8.7) 6 (12.5) 14 (29.2) 14 (31.1) 17 (60.7) 2
(6.3)
Severe 2 (4.3) 9 (18.8) 5 (10.4) 6 (13.3) 3 (10.7) 0
Chills
Any 6 (13.0) 15 (31.3) 12 (25.0) 20 (44.4) 24 (85.7) 0
Mild 3 (6.5) 9 (18.8) 11 (22.9) 12 (26.7) 6 (21.4) 0
Moderate 2 (4.3) 4 (8.3) 8 (16.7) 4 (8.9) 14 (50.0) 0
Severe 1 (2.2) 2 (4.2) 1 (2.1) 4 (8.9) 4 (14.3) 0
Myalgia
Any 11 (23.9) 23 (47.9) 32 (66.7) 28 (62.2) 22 (78.6) 6
(18.8)
Mild 8 (17.4) 14 (29.2) 21 (43.8) 14 (31.1) 9 (32.1) 6
(18.8)
Moderate 3 (6.5) 7 (14.6) 10 (20.8) 10 (22.2) 12 (42.9) 0
Severe 0 2 (4.2) 1 (2.1) 4 (8.9) 1 (3.6) 0
Arthralgia
Any 6 (13.0) 14 (29.2) 18 (37.5) 17 (37.8) 16 (57.1) 0
Mild 6 (13.0) 11 (22.9) 10 (20.8) 10 (22.2) 11 (39.3) 0
Moderate 0 2 (4.2) 6 (12.5) 5 (11.1) 3 (10.7) 0
Severe 0 1 (2.1) 2 (4.2) 2 (4.4) 2 (7.1) 0
Nausea/ Vomiting
Any 3 (6.5) 9 (18.8) 9 (18.8) 10 (22.2) 11 (39.3) 2 (6.3)
Mild 2 (4.3) 7 (14.6) 7 (14.6) 10 (22.2) 7 925.0) 2 (6.3)
Moderate 1 (2.2) 2 (4.2) 1 (2.1) 0 3 (10.7) 0
Severe 0 0 1 (2.1) 0 1 (3.6) 0
Diarrhea
Any 3 (6.5) 7 (14.6) 10 (20.8) 3 (6.7) 5 (17.9) 5 (15.6)
Mild 3 (6.5) 7 (14.6) 7 (14.6) 3 (6.7) 5 (17.9) 5 (15.6)
Moderate 0 0 3 (6.3) 0 0 0
Severe 0 0 0 0 0 0
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Table 4b. Solicited systemic AEs with severity within 7 days
after the second dose
Severity 2 μg 4 μg 6 μg 8 μg 12 μg Placebo
N = 44 44 45 41 26 30
Fever
Any 1 (2.3) 3 (4.8) 12 (26.7) 12 (29.3) 14 (53.8) 0
Mild 1 (2.3) 2 4.5) 8 (17.8) 6 (14.6) 5 (19.2) 0
Moderate 0 0 3 (6.7) 3 (7.3) 6 (23.1) 0
Severe 0 1 (2.3) 1 (2.2) 3 (7.2) 3 (11.5) 0
Headache
Any 12 (27.3) 26 (59.1) 30 (66.6) 33 (80.5) 22 (84.6) 7
(23.3)
Mild 8 (18.2) 16 (36.4) 17 (37.8) 16 (39.0) 5 (19.2) 6
(20.0)
Moderate 3 (6.8) 8 (18.2) 9 (20.0) 12 (29.3) 14 (53.8) 1
(3.3)
Severe 0 2 (4.5) 4 (8.8) 5 (12.2) 3 (11.5) 0
Fatigue
Any 13 (29.5) 25 (56.8) 28 (62.2) 34 (82.9) 25 (96.2) 5
(16.7)
Mild 9 (20.5) 16 (36.3) 16 (35.6) 19 (46.3) 8 (30.8) 5
(16.7)
Moderate 4 (9.0) 4 (9.0) 8 (17.8) 10 (24.4) 15 (57.7) 0
Severe 0 5 (11.4) 4 (8.9) 5 (12.2) 2 (7.7) 0
Chills
Any 4 (9.1) 7 (15.9) 15 (33.3) 15 (36.6) 21 (80.8) 0
Mild 3 (6.8) 3 (6.8) 9 (20.0) 8 (19.5) 5 (19.2) 0
Moderate 1 (2.3) 3 (6.8) 5 (11.1) 4 (9.8) 12 (46.2) 0
Severe 0 1 (2.3) 1 (2.2) 3 (7.3) 4 (15.4) 0
Myalgia
Any 7 (15.9) 15 (34.1) 23 (51.1) 20 (48.8) 19 (73.1) 1 (3.3)
Mild 6 (13.3) 9 (20.5) 15 (33.3) 11 (26.8) 10 (38.5) 1 (3.3)
Moderate 1 (2.3) 4 (9.1) 7 (15.6) 7 (17.1) 8 (30.8) 0
Severe 0 2 (4.5) 1 (2.2) 2 (4.9) 1 (3.8) 0
Arthralgia
Any 1 (2.3) 8 (18.2) 15 (33.3) 12 (29.3) 11 (42.3) 0
Mild 1 (2.3) 6 (13.3) 7 (15.5) 9 (22.0) 7 (26.9) 0
Moderate 0 1 (2.3) 4 (8.9) 2 (4.9) 2 (7.7) 0
Severe 0 1 (2.3) 2 (4.4) 1 (2.4) 2 (7.7) 0
Nausea/ Vomiting
Any 1 (2.3) 6 (13.3) 6 (13.3) 8 (19.5) 7 (26.9) 1 (3.3)
Mild 1 (2.3) 4 (9.0) 4 (8.9) 8 (19.5) 5 (19.2) 1 (3.3)
Moderate 0 2 (4.5) 1 (2.2) 0 2 (7.7) 0
Severe 0 0 1 (2.2) 0 0 0
Diarrhea
Any 0 2 (4.5) 5 (11.1) 3 (2.4) 3 (11.5) 5 (16.7)
Mild 0 2 (4.5) 3 (6.7) 1 (2.4) 3 (11.5) 5 (16.7)
Moderate 0 0 2 (4.4) 0 0 0
Severe 0 0 0 0 0 0
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Table 5. Seroconversion rates in each group at each time-point,
n/N (%)
Fold-increase 2 μg 4 μg 6 μg 8 μg 12 μg
S protein IgG
Day 29 ≥ 4 2/35
(6)
6/36
(17)
6/38
(16)
10/36
(28)
2/11
(18)
Day 36 ≥ 4 17/35
(49)
25/34
(74)
26/35
(74)
24/35
(69)
9/11
(82)
Day 43 ≥ 4 26/33
(79)
27/33
(82)
26/37
(70)
28/35
(80)
10/11
(91)
RBD IgG
Day 36 ≥ 4 6/35
(17)
15/34
(44)
12/34
(35)
23/35
(66)
6/11
(55)
Day 43 ≥ 4 13/33
(39)
26/33
(79)
25/36
(69)
29/35
(83)
10/11
(91)
Virus neutralizing titers
Day 36 ≥ 4 12/35
(34)
13/35
(37)
11/34
(32)
21/35
(60)
7/11
(64)
Day 43 ≥ 4 24/33
(73)
21/32
(66)
20/36
(56)
27/35
(77)
11/11
(100)
Table 6. Ratio of neutralizing to binding antibodies in
vaccinated and convalescent subjects
Dose VNTs/RBD IgG VNT/Spike IgG
12µg 0.0806 0.0218
HCS 0.0832 0.0213
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Figure 1. CONSORT Flow Chart
Randomization
EnrolledN = 248
Group1
2 μg
n = 47
Group 3
6 μg
n = 48
Group 2
4 μg
n = 48
Group 4
8 μg
n = 45
Received 2nd
dose
n = 45
Received 2nd
dose
n = 45
Received 2nd
dose
n = 44
Received 2nd
dose
n = 41
Samples available
n = 35Samples available
n = 34
Samples available
n = 34
Samples available
n = 35
Day 1
Received
Dose 1
Day 29
Received
Dose 2
Safetyset
Group 5
12 μg
n = 28
Received 2nd
dose
n = 26
Samples available
n = 11
Samples available
n = 30
1 adverse event
1 subject withdrew
1 adverse event
1 lost to follow up
2 Other
1 adverse event
1 lost to follow up
1 Other
1 subject withdrew
3 Other
1 adverse event
1 other
1 adverse event
1 Other
Per protocol
set
Group1
2 μg
n = 48
Group 3
6 μg
n = 48
Group 2
4 μg
n = 48
Group 4
8 μg
n = 45
AssignedGroup 5
12 μg
n = 28
Immunologyassessments
1 subject withdrew
Placebo
n = 32
Received 2nd
dose
n = 30
Placebo
n = 32
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Figure 2. Overall incidence rates (%) of solicited local and
systemic AEs per group with severity after the first and second
doses
Perc
en
tag
e o
f p
art
icip
nats
Solicited local AEs Solicited systemic AEs
1st dose 1st dose
2nd dose 2nd dose
Mild Moderate Severe
0
20
40
60
80
100
Placebo 2 μg 4 μg 6 μg 8 μg 12 μg
0
20
40
60
80
100
Placebo 2 μg 4 μg 6 μg 8 μg 12 μg
0
20
40
60
80
100
Placebo 2 μg 4 μg 6 μg 8 μg 12 μg
0
20
40
60
80
100
Placebo 2 μg 4 μg 6 μg 8 μg 12 μg
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Figure 3. Anti-Spike protein IgG in the different study groups
and convalescent sera measured
by ELISA. Bars show median values per group at each study
timepoint, individual
GMT values for each sample shown as diamonds. Numbers show
median values at
Day 43, two weeks after the second vaccination, for each group
and in the
convalescent sera.
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Figure 4. Anti-RBD IgG in the different study groups and
convalescent sera measured by
ELISA. Bars show median values per group at each study
timepoint, individual GMT
values for each sample shown as diamonds. Numbers show median
values at Day
43, two weeks after the second vaccination, for each group and
in the convalescent
sera.
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Figure 5. Anti-SARS-CoV-2 virus neutralizing titers in the
different study groups and
convalescent sera measured by microneutralization. Bars show
median values per
group at each study timepoint, individual GMT values for each
sample shown as
diamonds. Numbers show median MN50 values at Day 43, two weeks
after the
second vaccination, for each group and in the convalescent
sera.
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Tables and Figures pertaining to subjects not known to be
seropositive at baseline (Table 7 to 9 and Figure 6)
Table 7 Demographic and Baseline
Characteristics - Safety Population Previously SARS-nCoV-2
seropositives
Cohort 1
(2 ug)
Cohort 2
(4 ug)
Variable Category Statistic (N=8) (N=8)
Age (Years) Mean (SD) 39.6 (12.58) 39.1 (12.45)
Median 41 41
Min, Max (20, 54) (19, 54)
Gender Male n (%) 5 (63%) 6 (75%)
Female n (%) 3 (38%) 2 (25%)
BMI (kg/m²) Mean (SD) 23.8 (2.076) 25.4 (3.464)
Median 24 26
Min, Max (21, 28) (20, 30)
RACE Asian n (%) 0 (0%) 0 (0%)
White n (%) 8 (100%) 8 (100%)
Ethnicity Not Hispanic or Latino n (%) 8 (100%) 8 (100%)
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Table 8. Solicited local AEs with severity after one dose
Severity 2 μg 4 μg
N = 8 8
Pain
Any 8 (100.0) 6 (75.0)
Mild 8 (100.0) 6 (75.0)
Moderate 0 0
Severe 0 0
Redness Any 0 0
Sweilling Any 0 0
Itching Any 0 0
N= 8 7
Pain
Any 5 (62.5) 5 (71.4)
Mild 5 (62.5) 5 (71.4)
Moderate 0 0
Severe 0 0
Redness Any 0 0
Sweilling Any 0 0
Itching
Any 0 0
Mild 0 0
Moderate 0 0
Severe 0 0
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Table 9a. Solicited systemic AEs with severity within 7 days
after the first dose
Severity 2 μg 4 μg
N = 8 8
Fever
Any 0 2 (25.0)
Mild 0 1 (12.5)
Moderate 0 1 (12.5)
Severe 0 0
Headache
Any 3 (37.5) 5 (62.5)
Mild 3 (37.5) 5 (62.5)
Moderate 0 0
Severe 0 0
Fatigue
Any 5 (62.5) 5 (62.5)
Mild 4 (50.0) 3 (37.5)
Moderate 1 (12.5) 2 (25.0)
Severe 0 0
Chills
Any 0 3 (37.5)
Mild 0 2 (25.0)
Moderate 0 1 (12.5)
Severe 0 0
Myalgia
Any 2 (25.0) 4 (50.0)
Mild 2 (25.0) 3 (37.5)
Moderate 0 1 (12.5)
Severe 0 0
Arthralgia
Any 0 2 (25.0)
Mild 0 2 (25.0)
Moderate 0 0
Severe 0 0
Nausea/ Vomiting
Any 1 (12.5) 1 (12.5)
Mild 1 (12.5) 1 (12.5)
Moderate 0 0
Severe 0 0
Diarrhea
Any 1 (12.5) 1 (12.5)
Mild 1 (12.5) 1 (12.5)
Moderate 0 0
Severe 0 0
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Table 9b. Solicited systemic AEs with severity within 7 days
after the second dose
Severity 2 μg 4 μg
N = 8 7
Fever
Any 0 0
Mild 0 0
Moderate 0 0
Severe 0 0
Headache
Any 3 (37.5) 4 (57.2)
Mild 2 (25.0) 3 (42.9)
Moderate 1 (12.5) 0
Severe 0 1 (14.3)
Fatigue
Any 4 (50.0) 4 (57.2)
Mild 3 (37.5) 3 (42.9)
Moderate 1 (12.5) 0
Severe 0 1 (14.3)
Chills
Any 1 (12.5) 0
Mild 1 (12.5) 0
Moderate 0 0
Severe 0 0
Myalgia
Any 2 (25.0) 1 (14.3)
Mild 2 (25.0) 1 (14.3)
Moderate 0) 0
Severe 0 0
Arthralgia
Any 0 3 (42.9)
Mild 0 3 (42.9)
Moderate 0 0
Severe 0 0
Nausea/ Vomiting
Any 0 1 (14.3)
Mild 0 1 (14.3)
Moderate 0 0
Severe 0 0
Diarrhea
Any 0 0
Mild 0 0
Moderate 0 0
Severe 0 0
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Figure 6. Boosting of antibody responses in seropositive
subjects.
Seropositve subjects were vaccinated either with 2µg (upper
panel) or 4µg (lower panel)
of CVnCoV on day 1 and 29. RBD binding antibodies as well as
SARS-CoV-2 antibodies
were analyzed on multiple time points. Lines show individual
subjects in both dose
groups.
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